Results of tests with Marines at Camp Pendleton, Calif. indicate that a hand-held display viewed at a distance of one to three feet does not perform sufficiently well enough for many field operations. In direct sunlight, this display becomes very difficult to read due to glare and light saturation. The glare inhibits adequate read-ability of current display technologies. At night, a hand-held display reduces night vision and betrays tactical positions. Tactical positioning is jeopardized by light emission from the hand-held display, a circumstance often remedied in the field by reading the display under a cloth covering. Plainly, such a solution eliminates situational awareness of the surrounding environment.
It is believed that commercially available devices fail to adequately address the needs of the Marines or other users in this and other applications in this regard. For example, PCT Application No. WO 95/24713 to Fischer et al., incorporated herein by reference, discloses head-mounted display systems for the viewing of video or other sources of imagery which comprises a mechanism allowing a wide range of adjustments for presenting a display to the wearer. The various head-mounted display systems described can include rubber eyecups integrated into their video module so as to keep all stray ambient light out of the system. The Fischer et al. system prevents situational awareness during operation thereof. Use of the Fischer et al. system invites temporary blindness, at night, for example, upon removal of the system to regain situational awareness. Such temporary blindness inhibits immediate situational awareness.